Air Polycyclic Aromatic Hydrocarbons (PAHs) associated with PM2.5 in a North Cantabric coast urban environment.

Health studies and more specifically epidemiological studies require an extended analysis of the physical and chemical characteristics of the environment in which are held. The aim of this study is to evaluate the concentration of six Polycyclic Aromatic Hydrocarbons (PAHs) in PM2.5 fraction of air in a peri-urban environment in the province of Gipuzkoa (Basque Country, Spain) where residential areas are surrounded by industrial activity. The six studied PAH are as follows: Fluoranthene, Benzo(b)fluoranthene, Benzo(k)fluoranthene, (Benzo(a)pyrene, Indene(123-cd)pyrene and Benzo(ghi)perylene. Our six-year study shows a decrease in PAH concentrations between 2006 and 2011, especially since 2008 due to the fall in industrial activity and related traffic. Overall, 801 data were obtained. Total PAH concentration ranged between 0.3 and 8.29ngm(-3) and Benzo(a)pyrene (BaP) from 0.05 to 0.88ngm(-3). The mean value for BaP in PM2.5 was 0.15ngm(-3) and the target value established by European legislation in PM10 was only exceeded in occasional days. Contribution percentages of each PAH in the monitoring sites were very similar, indicating common sources. The results of this study suggest that emission from industry play an important role although we also have to consider the contribution of traffic. PAH seasonal variations are similar as those reported in many previous studies. BaP and PAH concentration values in our region of study were in the range of other Spanish cities.